Parathyroid C59 P452-458 Flashcards Preview

Section II General Surgery P203Surgical Recall Sixth > Parathyroid C59 P452-458 > Flashcards

Flashcards in Parathyroid C59 P452-458 Deck (58):
1

ANATOMY
How many parathyroids are
there?
P452

Usually four (two superior and two
inferior)

2

ANATOMY
What percentage of patients
have five parathyroid glands?
P452

≈5% (Think: 5 = 5)

3

ANATOMY
What percentage of patients
have three parathyroid
glands?
P452

≈10%

4

ANATOMY
What is the usual position of
the inferior parathyroid
glands?
P452

Posterior and lateral behind the thyroid
and below the inferior thyroid artery

5

ANATOMY
What is the most common
site of an “extra” gland?
P452

Thymus gland

6

ANATOMY
What percentage of patients
have a parathyroid gland in
the mediastinum?
P452

≈1%

7

ANATOMY
If only three parathyroid
glands are found at surgery,
where can the fourth one
be hiding?
P452

Thyroid gland
Thymus/mediastinum
Carotid sheath
Tracheoesophageal groove
Behind the esophagus

8

ANATOMY
What is the embryologic
origin of the following structures:
Superior parathyroid glands?
P453

Fourth pharyngeal pouch

9

ANATOMY
What is the embryologic
origin of the following structures:
Inferior parathyroid glands?
P453

Third pharyngeal pouch
(counterintuitive)

10

ANATOMY
What supplies blood to the
parathyroid glands?
P453

Inferior thyroid artery

11

ANATOMY
What percentage of patients
have all four parathyroid
glands supplied by the
inferior thyroid arteries
exclusively?
P453

≈80%

12

ANATOMY
What is DiGeorge’s
syndrome?
P453

Congenital absence of the parathyroid
glands and the thymus

13

ANATOMY
What is the most common
cause of hypercalcemia in
hospitalized patients?
P453

Cancer

14

ANATOMY
What is the most common
cause of hypercalcemia in
outpatients?
P453

Hyperparathyroidism

15

PHYSIOLOGY
What cell type produces
PTH?
P453

Chief cells produce ParaThyroid
Hormone (PTH)

16

PHYSIOLOGY
What are the major actions
of PTH?
P453

Increases blood calcium levels (takes
from bone breakdown, GI absorption,
increased resorption from kidney,
excretion of phosphate by kidney),
decreases serum phosphate

17

PHYSIOLOGY
How does vitamin D work?
P453

Increases intestinal absorption of calcium
and phosphate

18

PHYSIOLOGY
Where is calcium absorbed?
P453

Duodenum and proximal jejunum

19

HYPERPARATHYROIDISM (HPTH)
Define primary HPTH.
P454

Increased secretion of PTH by parathyroid
gland(s); marked by elevated calcium,
low phosphorus

20

HYPERPARATHYROIDISM (HPTH)
Define secondary HPTH.
P454

Increased serum PTH resulting from
calcium wasting caused by renal failure
or decreased GI calcium absorption,
rickets or osteomalacia; calcium levels
are usually low

21

HYPERPARATHYROIDISM (HPTH)
Define tertiary HPTH.
P454

Persistent HPTH after correction of
secondary hyperparathyroidism; results
from autonomous PTH secretion not
responsive to the normal negative
feedback due to elevated Ca⁺ ⁺ levels

22

HYPERPARATHYROIDISM (HPTH)
What are the methods of
imaging the parathyroids?
P454

Surgical operation
Ultrasound
Sestamibi scan
201TI (technetium)–thallium subtraction
scan
CT/MRI
A-gram (rare)
Venous sampling for PTH (rare)

23

HYPERPARATHYROIDISM (HPTH)
What are the indications for
a localizing preoperative
study?
P454

Reoperation for recurrent
hyperparathyroidism

24

HYPERPARATHYROIDISM (HPTH)
What is the most common
cause of primary HPTH?
P454

Adenoma ( >85%)

25

HYPERPARATHYROIDISM (HPTH)
What are the etiologies
of primary HPTH and
percentages?
P454

Adenoma ( ≈85%)
Hyperplasia ( ≈10%)
Carcinoma ( ≈1%)

26

HYPERPARATHYROIDISM (HPTH)
What is the incidence of
primary HPTH in the
United States?
P454

≈1/1000–4000

27

HYPERPARATHYROIDISM (HPTH)
What are the risk factors for
primary HPTH?
P454

Family history, MEN-I and MEN-IIa,
irradiation

28

HYPERPARATHYROIDISM (HPTH)
What are the signs/
symptoms of primary HPTH
hypercalcemia?
P455

“Stones, bones, groans, and
psychiatric overtones”:
Stones: Kidney stones
Bones: Bone pain, pathologic
fractures, subperiosteal resorption
Groans: Muscle pain and weakness,
pancreatitis, gout, constipation
Psychiatric overtones: Depression,
anorexia, anxiety
Other symptoms: Polydipsia, weight
loss, HTN (10%), polyuria, lethargy

29

HYPERPARATHYROIDISM (HPTH)
What is the “33 to 1” rule?
P455

Most patients with primary HPTH have a
ratio of serum (Cl⁻) to phosphate ≥33

30

HYPERPARATHYROIDISM (HPTH)
What plain x-ray findings are
classic for HPTH?
P455

Subperiosteal bone resorption (usually in
hand digits; said to be “pathognomonic”
for HPTH!)

31

HYPERPARATHYROIDISM (HPTH)
How is primary HPTH
diagnosed?
P455

Labs—elevated PTH (hypercalcemia,
↓ phosphorus, ↑ chloride); urine calcium
should be checked for familial
hypocalciuric hypercalcemia

32

HYPERPARATHYROIDISM (HPTH)
What is familial hypocalciuric
hypercalcemia?
P455

Familial (autosomal-dominant)
inheritance of a condition of
asymptomatic hypercalcemia
and low urine calcium, with or
without elevated PTH; in contrast,
hypercalcemia from HPTH results in
high levels of urine calcium
Note: Surgery to remove parathyroid
glands is not indicated for this diagnosis

33

HYPERPARATHYROIDISM (HPTH)
How many of the glands are USUALLY affected by the
following conditions:
Hyperplasia?
P455

4

34

HYPERPARATHYROIDISM (HPTH)
How many of the glands are USUALLY affected by the
following conditions:
Adenoma?
P455

1

35

HYPERPARATHYROIDISM (HPTH)
How many of the glands are USUALLY affected by the
following conditions:
Carcinoma?
P455

1

36

HYPERPARATHYROIDISM (HPTH)
What percentage of adenomas
are not single but found in
more than one gland?
P455

≈5%

37

HYPERPARATHYROIDISM (HPTH)
What is the differential
diagnosis of hypercalcemia?
P456

“CHIMPANZEES”:
Calcium overdose
Hyperparathyroidism (1/2/3),
Hyperthyroidism, Hypocalciuric
Hypercalcemia (familial)
Immobility/Iatrogenic (thiazide
diuretics)
Metastasis/Milk alkali syndrome (rare)
Paget’s disease (bone)
Addison’s disease/acromegaly
Neoplasm (colon, lung, breast,
prostate, multiple myeloma)
Zollinger-Ellison syndrome
Excessive vitamin D
Excessive vitamin A
Sarcoid

38

HYPERPARATHYROIDISM (HPTH)
What is the initial medical
treatment of hypercalcemia
(1 HPTH)?
P456

Medical—IV fluids, furosemide—NOT
thiazide diuretics

39

HYPERPARATHYROIDISM (HPTH)
What is the definitive treatment of HPTH in the
following cases:
Primary HPTH resulting
from HYPERPLASIA?
P456

Neck exploration removing all
parathyroid glands and leaving at least
30 mg of parathyroid tissue placed in the
forearm muscles (nondominant arm, of
course!)

40

HYPERPARATHYROIDISM (HPTH)
What is the definitive treatment of HPTH in the
following cases:
Primary HPTH resulting
from parathyroid
ADENOMA?
P456

Surgically remove adenoma (send for
frozen section) and biopsy all abnormally
enlarged parathyroid glands (some
experts biopsy all glands)

41

HYPERPARATHYROIDISM (HPTH)
What is the definitive treatment of HPTH in the
following cases:
Primary HPTH resulting
from parathyroid
CARCINOMA?
P456

Remove carcinoma, ipsilateral thyroid
lobe, and all enlarged lymph nodes
(modified radical neck dissection for LN
metastases)

42

HYPERPARATHYROIDISM (HPTH)
What is the definitive treatment of HPTH in the
following cases:
Secondary HPTH?
P456

Correct calcium and phosphate; perform
renal transplantation (no role for
parathyroid surgery)

43

HYPERPARATHYROIDISM (HPTH)
Tertiary HPTH?
P457

Correct calcium and phosphate; perform
surgical operation to remove all parathyroid
glands and reimplant 30 to 40 mg in the
forearm if REFRACTORY to medical
management

44

HYPERPARATHYROIDISM (HPTH)
Why place 30 to 40 mg of
sliced parathyroid gland in
the forearm?
P457

To retain parathyroid function; if HPTH
recurs, remove some of the parathyroid
gland from the easily accessible forearm

45

HYPERPARATHYROIDISM (HPTH)
What must be ruled out in
the patient with HPTH from
hyperplasia?
P457

MEN type I and MEN type IIa

46

HYPERPARATHYROIDISM (HPTH)
What carcinomas are
commonly associated with
hypercalcemia?
P457

Breast cancer metastases, prostate
cancer, kidney cancer, lung cancer,
pancreatic cancer, multiple myeloma

47

HYPERPARATHYROIDISM (HPTH)
What is the most likely
diagnosis if a patient has a
PALPABLE neck mass,
hypercalcemia, and elevated
PTH?
P457

Parathyroid carcinoma (vast majority
of other causes of primary HPTH have
nonpalpable parathyroids)

48

PARATHYROID CARCINOMA
What is it?
P457

Primary carcinoma of the parathyroid
gland

49

PARATHYROID CARCINOMA
What is the number of
glands usually affected?
P457

1

50

PARATHYROID CARCINOMA
What are the signs/
symptoms?
P457

Hypercalcemia, elevated PTH,
PALPABLE parathyroid gland (50%),
pain in neck, recurrent laryngeal nerve
paralysis (change in voice), hypercalcemic
crisis (usually associated with calcium
levels > 14)

51

PARATHYROID CARCINOMA
What is the common tumor
marker?
P457

Human Chorionic Gonadotropin
(HCG)

52

PARATHYROID CARCINOMA
What is the treatment?
P457

Surgical resection of parathyroid mass
with ipsilateral thyroid lobectomy,
ipsilateral lymph node resection

53

PARATHYROID CARCINOMA
What percentage of all
cases of primary HPTH
are caused by parathyroid
carcinoma?
P458

1%

54

PARATHYROID CARCINOMA
POSTOPERATIVE COMPLICATIONS OF PARATHYROIDECTOMY
What are the possible
postoperative complications
after a parathyroidectomy?
P458

Recurrent nerve injury (unilateral: voice
change; bilateral: airway obstruction),
neck hematoma (open at bedside if
breathing is compromised), hypocalcemia,
superior laryngeal nerve injury

55

PARATHYROID CARCINOMA
POSTOPERATIVE COMPLICATIONS OF PARATHYROIDECTOMY
What is “hungry bone
syndrome”?
P458

Severe hypocalcemia seen after surgical
correction of HPTH as chronically
calcium-deprived bone aggressively
absorbs calcium

56

PARATHYROID CARCINOMA
POSTOPERATIVE COMPLICATIONS OF PARATHYROIDECTOMY
What are the signs/
symptoms of postoperative
hypocalcemia?
P458

Perioral tingling, paresthesia,
+ Chvostek’s sign, + Trousseau’s sign,
+ tetany

57

PARATHYROID CARCINOMA
POSTOPERATIVE COMPLICATIONS OF PARATHYROIDECTOMY
What is the treatment of
hypoparathyroidism?
P458

Acute: IV calcium
Chronic: PO calcium, and vitamin D

58

PARATHYROID CARCINOMA
POSTOPERATIVE COMPLICATIONS OF PARATHYROIDECTOMY
What is parathyromatosis?
P458

Multiple small hyperfunctioning
parathyroid tissue masses found over the
neck and mediastinum—thought to be
from congenital rests or spillage during
surgery—remove surgically (RARE)